With the development of technology, it is a general trend to incorporate a touch control screen on a mobile device. There is a need in the market to provide a proximity sensor in a mobile device that can detect the user's head or face so as to turn off the touch control screen when the mobile device is in use, thereby preventing the touch control screen from being mistouched by the user and interfering with an ongoing call.
With smart phones as an example, the conventional sensing module used therein includes an emitter, a proximity receptor, and an ambient light receptor. The proximity receptor and the ambient light receptor are disposed in different chambers of a package casing to avoid crosstalk effects. The emitter is disposed on a circuit substrate and the two receptors are chips disposed on the circuit substrate. The package casing has a plurality of holes that respectively correspond in position to the emitter, the proximity receptor, and the ambient light receptor.
However, in current designs, the bulk of the package casing causes the proximity sensing module to occupy a large volume of space inside the smart phone. To meet miniaturization requirements of electronic devices, the proximity sensing module also needs to be miniaturized. In addition, to achieve a better sensing effect, the sensor is preferably designed to have a wide sensing angle. However, the crosstalk effect in the sensing module generally increases with the increase of the sensing angle. Moreover, the sensing angle of the sensor would be restricted by the height and the thickness of the package casing. Furthermore, current market demands require that the mobile devices be designed with smaller and a reduced number of visible holes. In conclusion, there is still need in the art to provide a replacement solution to the conventional sensing module.